re: Flutter, Ionic, React Native or Xamarin? What you use and why? VIEW POST

This talk explains it in more detail, but the key trade-off is that React Native makes use of native platform widgets whereas Flutter rolls its own widgets. It is an oversimplification, but:

React Native has more chance of looking and working like a native application.

Flutter has more chance of meeting the performance requirements of a native application.

Inherent to understanding the trade-off is that in order to use platform native widgets React Native needs to bridge or map calls between interpreted JavaScript and platform native code, which has a performance cost.

Flutter gains performance both avoiding the overhead of this intermediary layer and also (in production/release mode) by running compiled code (hence Dart).

Neither is likely to ever be as good as writing a native application, but both have the potential to be good enough.